[PATCH v13 1/3] dt-bindings: adc: add AD7173

From: Dumitru Ceclan
Date: Tue Feb 20 2024 - 04:48:09 EST

The AD7173 family offer a complete integrated Sigma-Delta ADC solution
which can be used in high precision, low noise single channel applications
or higher speed multiplexed applications. The Sigma-Delta ADC is intended
primarily for measurement of signals close to DC but also delivers
outstanding performance with input bandwidths out to ~10kHz.

Signed-off-by: Dumitru Ceclan <mitrutzceclan@xxxxxxxxx>
---
V12->V13
- Remove adi,clock-select
- Update avdd and avdd2 supply descriptions
- Update adi,reference-select description to suggest that it is referenced to avss
- Make clocks/clock-names and clock-controller mutually exclusive
V11->V12
- Drop "binding", describe hardware in binding description
- Rename refin and refin2 to vref and vref2
- Add better description to external references to better show that the voltage
value that needs to be specified is the difference between the positive and
negative reference pins
- Add optional clocks properties
- Add optional adi,clock-select property
- Add option for second interrupt, error
- Add description to interrupts
V10->V11
- Fix example warning: '#gpio-cells' is a dependency of 'gpio-controller'
- Add description to #gpio-cells property
V9->V10
- Fix dt_binding_check type warning from adi,reference-select
V8->v9
- Add gpio-controller and "#gpio-cells" properties
- Add missing avdd2 and iovdd supplies
- Add string type to reference-select
V7->V8
- include missing fix from V6
V6->V7 <no changes>
V5->V6
- Moved global required property to proper placement
V4 -> V5
- Use string enum instead of integers for "adi,reference-select"
- Fix conditional checking in regards to compatible
V3 -> V4
- include supply attributes
- add channel attribute for selecting conversion reference
V2 -> V3
- remove redundant descriptions
- use referenced 'bipolar' property
- remove newlines from example
V1 -> V2 <no changes>

.../bindings/iio/adc/adi,ad7173.yaml | 242 ++++++++++++++++++
1 file changed, 242 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
new file mode 100644
index 000000000000..347a0cc0e278
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
@@ -0,0 +1,242 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2023 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7173.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD7173 ADC
+
+maintainers:
+ - Ceclan Dumitru <dumitru.ceclan@xxxxxxxxxx>
+
+description: |
+ Analog Devices AD717x ADC's:
+ The AD717x family offer a complete integrated Sigma-Delta ADC solution which
+ can be used in high precision, low noise single channel applications
+ (Life Science measurements) or higher speed multiplexed applications
+ (Factory Automation PLC Input modules). The Sigma-Delta ADC is intended
+ primarily for measurement of signals close to DC but also delivers
+ outstanding performance with input bandwidths out to ~10kHz.
+
+ Datasheets for supported chips:
+ https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-2.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/AD7176-2.pdf
+
+properties:
+ compatible:
+ enum:
+ - adi,ad7172-2
+ - adi,ad7173-8
+ - adi,ad7175-2
+ - adi,ad7176-2
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ minItems: 1
+ description: |
+ Ready interrupt: multiplexed with SPI data out. While SPI CS is low,
+ can be used to indicate the completion of a conversion.
+
+ Error: The three error bits in the status register (ADC_ERROR, CRC_ERROR,
+ and REG_ERROR) are OR'ed, inverted, and mapped to the ERROR pin. Therefore,
+ the ERROR pin indicates that an error has occurred.
+
+ interrupt-names:
+ minItems: 1
+ items:
+ - const: rdy
+ - const: err
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+ spi-max-frequency:
+ maximum: 20000000
+
+ gpio-controller:
+ description: Marks the device node as a GPIO controller.
+
+ '#gpio-cells':
+ const: 2
+ description:
+ The first cell is the GPIO number and the second cell specifies
+ GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
+
+ vref-supply:
+ description: |
+ Differential external reference supply used for conversion. The reference
+ voltage (Vref) specified here must be the voltage difference between the
+ REF+ and REF- pins: Vref = (REF+) - (REF-).
+
+ vref2-supply:
+ description: |
+ Differential external reference supply used for conversion. The reference
+ voltage (Vref2) specified here must be the voltage difference between the
+ REF2+ and REF2- pins: Vref2 = (REF2+) - (REF2-).
+
+ avdd-supply:
+ description: Avdd supply, can be used as reference for conversion.
+ This supply is referenced to AVSS, voltage specified here
+ represens (AVDD - AVSS).
+
+ avdd2-supply:
+ description: Avdd2 supply, used as the input to the internal voltage regulator.
+ This supply is referenced to AVSS, voltage specified here
+ represens (AVDD2 - AVSS).
+
+ iovdd-supply:
+ description: iovdd supply, used for the chip digital interface.
+
+ clocks:
+ maxItems: 1
+ description: |
+ Optional external clock source. Can include one clock source: external
+ clock or external crystal.
+
+ clock-names:
+ enum:
+ - ext-clk
+ - xtal
+
+ '#clock-cells':
+ const: 0
+
+patternProperties:
+ "^channel@[0-9a-f]$":
+ type: object
+ $ref: adc.yaml
+ unevaluatedProperties: false
+
+ properties:
+ reg:
+ minimum: 0
+ maximum: 15
+
+ diff-channels:
+ items:
+ minimum: 0
+ maximum: 31
+
+ adi,reference-select:
+ description: |
+ Select the reference source to use when converting on
+ the specific channel. Valid values are:
+ vref : REF+ /REF−
+ vref2 : REF2+ /REF2−
+ refout-avss: REFOUT/AVSS (Internal reference)
+ avdd : AVDD /AVSS
+
+ External reference ref2 only available on ad7173-8.
+ If not specified, internal reference used.
+ $ref: /schemas/types.yaml#/definitions/string
+ enum:
+ - vref
+ - vref2
+ - refout-avss
+ - avdd
+ default: refout-avss
+
+ required:
+ - reg
+ - diff-channels
+
+required:
+ - compatible
+ - reg
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+ - if:
+ properties:
+ compatible:
+ not:
+ contains:
+ const: adi,ad7173-8
+ then:
+ properties:
+ vref2-supply: false
+ patternProperties:
+ "^channel@[0-9a-f]$":
+ properties:
+ adi,reference-select:
+ enum:
+ - vref
+ - refout-avss
+ - avdd
+
+ - if:
+ anyOf:
+ - required: [clock-names]
+ - required: [clocks]
+ then:
+ properties:
+ '#clock-cells': false
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "adi,ad7173-8";
+ reg = <0>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
+ interrupt-names = "rdy";
+ interrupt-parent = <&gpio>;
+ spi-max-frequency = <5000000>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ #clock-cells = <0>;
+
+ vref-supply = <&dummy_regulator>;
+
+ channel@0 {
+ reg = <0>;
+ bipolar;
+ diff-channels = <0 1>;
+ adi,reference-select = "vref";
+ };
+
+ channel@1 {
+ reg = <1>;
+ diff-channels = <2 3>;
+ };
+
+ channel@2 {
+ reg = <2>;
+ bipolar;
+ diff-channels = <4 5>;
+ };
+
+ channel@3 {
+ reg = <3>;
+ bipolar;
+ diff-channels = <6 7>;
+ };
+
+ channel@4 {
+ reg = <4>;
+ diff-channels = <8 9>;
+ adi,reference-select = "avdd";
+ };
+ };
+ };
--
2.42.0